The present invention relates to a sheet feeding device, and more particularly, to a type thereof having a plurality of rollers positioned side by side in a widthwise direction of a sheet to be transferred.
In a conventional laser printer, a word processor or a copying machine, a sheet feeding device is provided for transferring a sheet stacked in a sheet cassette or tray to an image recording portion such as a photosensitive drum and a print head. The conventional sheet feeding device has rollers whose rotation axes are aligned with each other in the widthwise direction of the sheet.
In such a conventional sheet feeding device, various forces are imparted on the sheet in addition to the sheet feeding force by the plurality of rollers. For example, additional roller is provided at upstream or downstream side of the plurality of rollers, which additional roller may provide sheet feed force or resistive force against sheet feeding. Further, the sheet to be transferred may be imparted with frictional force by the surface contact with succeeding sheet stacked on the sheet tray.
Particularly, for supplying the sheet on the sheet tray to the plurality of rollers, a sheet supply roller unit is provided upstream of the plurality of rollers. The sheet supply roller unit may be positioned offset from the widthwise center of the sheet to be transferred in order to make the sheet supply roller unit available for various kind of sheets of different width. With this arrangement, after the sheet reaches the plurality of rollers by the sheet supply roller unit yet the sheet is still in contact with the sheet supply roller, the sheet supply roller unit may provide a deviated resistive force against the sheet feeding force by the plurality of rollers.
Accordingly, resultant resistive force is not aligned with resultant sheet feeding force in the sheet feeding direction, so that the sheet may be imparted with rotational force. As a result, the sheet is oriented diagonally with respect to the sheet feeding direction, and consequently, a diagonal image may be provided on the sheet at the image recording portion.